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io_uring: mark known and harmless racy ctx->int_flags uses

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There are a few of these, where flags are read outside of the
uring_lock, yet it's harmless to race on them.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe
2026-03-14 08:46:17 -06:00
parent f1a424e21c
commit 8c55744919
3 changed files with 6 additions and 5 deletions
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2
io_uring/io_uring.c
View File

@@ -2242,7 +2242,7 @@ static __poll_t io_uring_poll(struct file *file, poll_table *wait)
struct io_ring_ctx *ctx = file->private_data;
__poll_t mask = 0;
if (unlikely(!(ctx->int_flags & IO_RING_F_POLL_ACTIVATED)))
if (unlikely(!(data_race(ctx->int_flags) & IO_RING_F_POLL_ACTIVATED)))
io_activate_pollwq(ctx);
/*
* provides mb() which pairs with barrier from wq_has_sleeper

7
io_uring/io_uring.h
View File

@@ -470,11 +470,12 @@ static inline void io_req_complete_defer(struct io_kiocb *req)
wq_list_add_tail(&req->comp_list, &state->compl_reqs);
}
#define SHOULD_FLUSH_MASK (IO_RING_F_OFF_TIMEOUT_USED | \
IO_RING_F_HAS_EVFD | IO_RING_F_POLL_ACTIVATED)
static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx)
{
if (unlikely(ctx->int_flags & (IO_RING_F_OFF_TIMEOUT_USED |
IO_RING_F_HAS_EVFD |
IO_RING_F_POLL_ACTIVATED)))
if (unlikely(data_race(ctx->int_flags) & SHOULD_FLUSH_MASK))
__io_commit_cqring_flush(ctx);
}

2
io_uring/tw.c
View File

@@ -222,7 +222,7 @@ void io_req_local_work_add(struct io_kiocb *req, unsigned flags)
if (!head) {
io_ctx_mark_taskrun(ctx);
if (ctx->int_flags & IO_RING_F_HAS_EVFD)
if (data_race(ctx->int_flags) & IO_RING_F_HAS_EVFD)
io_eventfd_signal(ctx, false);
}